Self-capping vapor-liquid-solid (VLS) growth of MoS2
Ming-Chiang Chang, Po-Hsun Ho, Mao-Feng Tseng, Fang-Yuan Lin, Cheng-Hung Hou, I-Kuan Lin, Hsin Wang, Pin-Pin Huang, Chun-Hao Chiang, Yueh-Chiang Yang, I-Ta Wang, He-Yun Du, Cheng-Yen Wen, Jing-Jong Shyue, Chun-Wei Chen, Kuei-Hsien Chen, Po-Wen Chiu & Li-Chyong Chen
Nature Commmunictions 11, 3682 (2020).
In this study, a self-capping vaporliquid-solid reaction is proposed to fabricate large-grain, continuous MoS2 films. An intermediate liquid phase-Na2Mo2O7 is formed through a eutectic reaction of MoO3 and NaF,followed by being sulfurized into MoS2. The as-formed MoS2 seeds function as a capping layer that reduces the nucleation density and promotes lateral growth. By tuning the driving force of the reaction, large mono/bilayer (1.1 mm/200 μm) flakes or full-coverage films (with a record-high average grain size of 450 μm) can be grown on centimeter-scale substrates. The field-effect transistors fabricated from the full-coverage films show high mobility (33 and 49 cm2V-1s-1 for the mono and bilayer regions) and on/off ratio (1 ~ 5 × 108) across a 1.5 cm × 1.5 cm region.